Generally, humidification of an electrolytic membrane in a fuel cell is important for the operation of the fuel cell. To this end, a humidification device is used. Such a humidification device operates such that dry gas supplied from the atmosphere to a fuel cell exchanges moisture with humid gas exhausted from the fuel cell.
A variety of humidification device types exist, for example, an ultrasonic humidification device, a steam humidification device, a vaporization humidification device, etc. However, a membrane humidifier using hollow fiber membranes has been used as an appropriate humidification device usable for fuel cells.
To this end, the present applicant proposed a fuel cell membrane module manufacturing method as disclosed in a patent application issued as a Korean Patent Registration No. 10-1382672 (Apr. 1, 2014). In this method, a membrane module for use in a membrane humidifier of a fuel cell is manufactured through implementation of a new hollow fiber membrane module structure in which a small number of hollow fiber membranes is arranged at a central portion of the module, and a gradually increased number of hollow fiber membranes is arranged toward a peripheral portion of the module. As such, uniform humidification performance is obtained throughout the entirerty of hollow fiber membranes in that dry air introduced from an air blower can be distributed toward the peripheral portion of the module where an increased number of hollow fiber membranes is arranged.
However, the above-mentioned registered patent has the following drawbacks.
First, in a variable pressure system in which the pressure of air introduced into a humidifier is high, there may be a leaning phenomenon in which hollow fiber membranes arranged in a membrane humidifier are inclined toward one side or a risk of breakage of hollow fiber membranes may exist. In this case, humidification efficiency may be severely lowered.
Second, in a potting process for dispersed arrangement of hollow fiber membranes, the hollow fiber membranes may be twisted.
Third, although a space for maintenance of the spacing between the adjacent hollow fiber membranes may be secured through a dispersed arrangement of the hollow fiber membranes, there is a drawback of an increase in unnecessary space.